I have wilk amethyst I think it's a 92 model
My lighting on one side of the caravan works perfectly fine, namely the front, outside and kitchen light. The bathroom, bedroom and water pump doesn't seem to be working. I've established that its not the bulbs, there is simply no power to these lights.
Where do I start looking and what testing tools do I require to test the wiring
Fuses, loose or damaged wiring ????
Start by looking if you can find any route from the lights and switches to the ISO charger/battery.
Also look underneath the caravan for wiring.
Then test with a voltmeter what voltage you are getting on the lights as well as light switches. It should be close to the battery voltage. It might help to connect a long piece of wire say 5m long on the battery negative to make sure you have a point for the negative when you test with the multimeter.
Share the results and we may offer further help.
Looks like the left and right sides are on different circuits and probably on different fuses. Check all fuses first.
As Danie stated connect a long wire to the negative side of the battery. Switch on the light switches. Then use the other end and touch the negative point on each light fitting. (Make sure it is the negative point).
If the light then works, you know that the negative wiring running from the battery to each light is at fault. (This neg wire does not go through the normal light switches is goes directly to the light fitting)
If you did this and still no lights working ............... tie the wire to the black terminal of a tester and then search at various points for the 12V coming from the battery. If I were you I will check the 12V wires coming out of the the Charger/DB box. Then the wires at the light switches. If you get a 12V reading at these places only other place to check is at the light fitting.
In my opinion it is maybe only the switch itself.